In recent years, in-vehicle cameras intended for drive assistance, and security cameras intended for assistance of crime prevention or criminal investigation have been increasingly developed and widespread. Those cameras not only allow a user to view picked-up images, but also are equipped with a function of automatically detecting lanes, vehicles, persons, and the motion of the persons through image processing. The image processing needs to capture data of a large number of pixels which is generally hundreds of thousands of pixels or more from an imaging element, and transfer and process the data. Further, in recent years, a high resolution of the imaging element is advanced, and a load of capturing, transferring, and processing the image has a tendency to be further increased. Also, in a stereo camera that measures three dimensions with the use of two cameras, a system in which a plurality of cameras is installed anterior to, posterior to, and lateral to a vehicle to monitor a periphery of the vehicle, or a security camera system in which a plurality of cameras is installed at different positions, because there is a need to process a plurality of images, the load of capturing, transferring, and processing the image is further increased.
Under the circumstances, a technique for limiting a region in which the images are captured, transferred, and processed is required. As the technique for limiting the region in which the image is processed, a method disclosed in Patent Literature 1 has been proposed. This is a technique in which if no vehicle is present at a short distance, a center portion of the images is processed without being thinned out, and if a vehicle is present at the short distance, the images are thinned out, and the overall images are processed. In the technique, one of the image of the unthinned center portion, and the image of the thinned overall images is selected according to the presence or absence of the vehicle. Alternatively, any one of a right region of the image and a left region of the image is selected on the basis of indicator information.    [Patent Literature 1] JP-A-2000-251080